Method:
1. Chop the orange skin finely.
2. Roast the tuvar dal and red chillies with one tsp oil.
3. Saute the orange peel also till it is soft.
4. When it is cooled down, mix all the ingredients and grind to a coarse/smooth paste. Tuvayal is ready.

You have to develop a taste for this as it may not be liked by everyone. Hence try with little quantity.